What is an orthodontic appliance, and how is it different from braces?
An orthodontic appliance is a removable or fixed device worn in the mouth that helps the jaws and teeth move into the correct position during growth or throughout treatment. It is usually used in children and adolescents while the jawbones are still growing, and its main goal is to influence not only the teeth but also the jaw structure and the space the teeth will occupy.
Braces (a bracket-and-wire system), on the other hand, mainly change the position of the existing teeth. An appliance and braces do not have to be alternatives to each other; in many patients the jaw relationship and available space are first corrected with an appliance, and then, if needed, the teeth are fine-tuned with braces or clear aligner treatment. Which path is suitable is determined by the orthodontist's examination together with an assessment of photographs and X-rays.
For a general overview, you can also read our article on intraoral devices. On this page we explain, in patient-friendly language, the main types of appliances used in orthodontics, how they work and what you may experience while using them.
Why are appliances important in childhood and during growth?
Appliances are important in childhood and during growth because the jawbones are still developing at this stage, and with the right guidance it is often possible to influence jaw structure. Once growth is complete, achieving the same changes usually requires more complex methods.
The aim of intervention during growth is to support harmony between the jaws, create enough room for the erupting permanent teeth and reduce the effect of harmful habits on jaw development. A suitable intervention at an early stage may reduce the need for more extensive orthodontic treatment or extractions later on; however, this does not apply to every child, and it would not be right to predict the outcome of any treatment in advance.
Not every child needs an appliance. For some children regular monitoring is enough, while for others early treatment is recommended. The decision is made at the examination based on the child's age, dental development, jaw relationship and growth potential. For clear aligner options at a young age, you can also visit our Invisalign First for children page.
What is the difference between removable and fixed appliances?
Removable appliances can be taken out and put back in by the patient, whereas fixed appliances are attached to the teeth with bands or bonding material and can only be removed by the dentist. Both are chosen according to the treatment plan, and they serve different functions.
Removable appliances include removable expansion plates, functional appliances such as the activator and Twin Block, Hawley-type retainers and habit-breaking plates. Their success depends largely on the patient wearing them regularly for the recommended time.
Fixed appliances include the rapid maxillary expander (RPE/Hyrax), the quad-helix, space maintainers and cribs for tongue-thrust habits. They depend less on patient cooperation but require more attention to oral hygiene.
With fixed devices, brushing takes longer; because plaque buildup around the device can lead to gum inflammation and tooth decay, brushing is supported with interdental brushes and mouthwash when needed. With removable devices, the most common problems are forgetting the device, losing it or not wearing it enough. That is why, when choosing a device for a child, the dentist also takes into account the child's cooperation and the family's support.
What is a palatal expander, and how does it work?
A palatal expander is an orthodontic device that creates slow, controlled widening in the palate of a narrow upper jaw, making room for the teeth and helping to correct problems such as crossbite. This section is the most detailed part of the page, because it is the topic families ask about most. For a shorter summary, you can also see our article on palatal expanders.
The upper jaw contains a palatal suture (a joining line) along the midline where two separate bones meet. During growth this suture is flexible; the light, gradual force applied by the device supports new bone formation in this area and increases the width of the jaw. The teeth do not simply tip outward; the bony base beneath them widens as well. In children with a narrow upper jaw, crossbite, crowding of the teeth and the risk of teeth becoming impacted can be addressed in this way. For details on crossbite, see our crossbite page.
What is rapid maxillary expansion (RPE / Hyrax)?
A rapid maxillary expander is a fixed device attached to the upper molars with bands and fitted with a screw in the middle. It is usually called an RPE (rapid palatal expander) or a Hyrax-type expander. When the screw is turned at set intervals, force is applied across the palatal suture and expansion is achieved in a short time, usually within a few weeks. It is commonly chosen for crossbite and marked narrowness of the upper jaw.
What do slow expansion and the quad-helix mean?
Slow expansion is an approach that widens the jaw with lighter forces over a longer period. The quad-helix is a fixed device made of a wire with four coils and is attached to the upper molars; it is usually preferred for milder narrowness and for correcting the inclination of the teeth. Slow expansion may be considered when the effect is expected to be mainly dental. The orthodontist decides which option is suitable.
What is a removable expansion plate?
A removable expansion plate consists of an acrylic plate that sits against the palate with a screw inside; the child can take it out and put it back in. It can be used for slow expansion in mild narrowness and during the primary and mixed dentition stages. Because it needs to be worn regularly, family support is important; its expansion capacity is more limited than that of fixed devices, and it is not suitable for every type of narrowness.
How does the screw-turning process work?
The screw-turning process means turning the screw in the middle of the device at a set frequency using a special key shown by the dentist; most families do this at home as part of the child's bedtime routine. The amount turned each time is very small. In the first days there may be a feeling of pressure and fullness in the palate and a slight change in speech; these complaints usually ease within a few days.
The direction and number of turns are demonstrated by the dentist in advance. Because skipping a turn, turning too much or turning in the wrong direction can disrupt treatment, contact the clinic whenever you are unsure. At check-up appointments the progress of the expansion is assessed and the turning plan is updated.
Why does a temporary gap appear between the front teeth during jaw expansion?
A temporary gap between the front teeth is a natural result of the two upper central incisors moving apart as the palatal suture opens, and it is generally interpreted as a sign that the expansion is working. The gap becomes more noticeable as the screw is turned. Children sometimes find this look strange, but knowing that it is temporary and part of the treatment makes cooperation easier. After expansion is complete, in most cases it closes on its own through the action of the soft tissues in the mouth or in a planned way during the later stages of orthodontic treatment. Families need not worry; however, the gap's progress is monitored at check-ups.
Up to what age is jaw expansion effective?
Jaw expansion is most effective in childhood and early adolescence, while the palatal suture is still flexible; the suture gradually stiffens and fuses during and after puberty. There is no exact age limit, as suture maturation varies from person to person. For this reason, rather than applying a very general rule, the child's growth status is assessed at the examination. Expansion carried out before growth is complete is generally expected to have a wider range of effect, while at older ages other methods may be considered.
Why is a retention period needed after expansion?
A retention period is needed because when expansion is complete, the newly formed bone has not yet fully matured and the jaw may tend to return to its former position. For this reason, after screw turning ends, the device is usually left fixed in the mouth for several months. Depending on how treatment is progressing, the patient may then move on to another device or to a retainer. The dentist decides on the length of the retention period; removing the device too early may cause some of the gained width to be lost.
What are the options for jaw expansion in adults?
In adults, jaw expansion is more complex because the palatal suture has matured, and the options are evaluated at the examination. As general information, MARPE (miniscrew-assisted rapid palatal expansion), which is anchored to the bone with mini screws, may be considered in some adult patients. For more pronounced narrowness, methods such as surgically assisted expansion may be considered; these are planned together with jaw surgery. Keep in mind that these options are not suitable for every patient, and an orthodontic examination is needed for a detailed assessment. For clear aligner treatment in adults, see our Invisalign for adults page.
Is jaw expansion possible with Invisalign First?
Invisalign First is a clear aligner system designed for children in the primary and mixed dentition stages, and in some cases it may be possible to achieve dental expansion and support the width of the upper arch. However, a clear aligner does not provide the same skeletal effect as a fixed expander that opens the palatal suture. When skeletal expansion is needed for marked narrowness of the upper jaw, a fixed expansion appliance is preferred; in some plans, an appliance may be used first, followed by clear aligners. For answers to questions about the effect on jaw structure, see our can clear aligners fix jaw structure page.
What are functional appliances, and how are they used for a retruded lower jaw?
Functional appliances are usually removable devices that use the force of the chewing, lip and tongue muscles to try to guide the lower jaw to grow in a more forward position. They are used in children who have a retruded lower jaw (where the upper teeth appear to protrude and the lower jaw sits back) and who still have growth potential.
The Twin Block consists of two acrylic plates that fit the upper and lower jaws separately; when the patient bites down, it guides the lower jaw forward. The activator is a one-piece device that covers both the upper and lower jaws. The Frankel appliance has a design that leaves space and reduces pressure from the cheek and lip muscles. What they all have in common is that they work in step with the growth period and require regular use. For more information on lower jaw position, take a look at our article on jaw repositioning appliances.
The effect of functional appliances depends on the rate of growth; for this reason, treatment is usually planned to start close to the growth spurt, and the child's skeletal development is assessed to find the right timing. In the first weeks there may be increased saliva, a temporary change in speech and some difficulty chewing; this usually settles as the device is worn regularly. Functional appliances are not designed to straighten teeth one by one; in most cases, fine-tuning with braces or clear aligners may be needed after this stage.
What are the face mask and headgear?
The face mask and headgear are orthopedic devices that take support from outside the mouth; the face mask is used to guide the upper jaw forward when it is retruded, while headgear is used to control the forward growth of the upper jaw or the molars. They are called "orthopedic" because their target is not only the teeth but the direction in which the jawbones grow.
The face mask is usually worn at an early age by children with a retruded upper jaw, together with an intraoral device, for certain hours of the day. For detailed information, read our article on the orthodontic face mask. Today, headgear is used more selectively and is mostly worn in the evening and at night. The duration and frequency of wear are set by the dentist; following the prescribed wear time directly affects how the outcome develops with these devices.
What is a space maintainer, and when is it used?
A space maintainer is a small appliance that prevents the gap left by a prematurely lost baby tooth from being closed by neighboring teeth and preserves the space where the permanent tooth will erupt. When a baby tooth is extracted early because of decay, a fracture or an accident, the neighboring teeth may drift into the gap, leaving no room for the permanent tooth waiting underneath.
Space maintainers can be fixed or removable; which one is suitable depends on the tooth that was lost and the child's age. When the permanent tooth begins to erupt, the dentist removes the device. For details, see our article on space maintainers.
What are habit-breaking appliances?
Habit-breaking appliances are small devices, usually placed against the palate, that help reduce the negative effects of thumb sucking, tongue thrusting and similar habits on tooth and jaw development. Prolonged thumb sucking, or pushing the tongue against the teeth while swallowing, can contribute to problems such as a gap between the front teeth (open bite) and a narrow jaw.
These devices usually take the form of a fixed crib or barrier and help the child relearn by making the habit physically harder. They may not be enough on their own; family support, motivation and, when needed, cooperation with a speech and language therapist improve the chances of success. You can also see our open bite page.
What are retention appliances (retainers)?
Retention appliances are devices that keep the teeth in their new position at the end of orthodontic treatment, and there are three main types: the Hawley retainer, the clear (vacuum-formed) retainer and the fixed (bonded wire) retainer. Because teeth tend to move back toward their original positions after treatment, wearing a retainer is an essential part of treatment.
A Hawley retainer consists of an acrylic plate that sits against the palate and a wire that runs around the front teeth; for details, see our article on the Hawley appliance. A clear retainer is a thin, custom-molded tray that fits over the teeth. A fixed retainer is a thin wire bonded to the inner surface of the front teeth. The dentist decides which type, or combination, is suitable. For the process after clear aligner treatment, see our retainer after clear aligners page.
Are night guards and anti-snoring devices orthodontic appliances?
Night guards and anti-snoring devices are not orthodontic appliances; rather than aligning the teeth, they are intraoral devices used, respectively, to reduce wear caused by clenching and grinding and to support the airway in snoring. They are often confused because they share the same name, "appliance".
For information on night guards, see our article on night guards; for anti-snoring devices, see our article on anti-snoring appliances. Snoring and sleep apnea are conditions that require medical evaluation; decisions on these matters are made only by the relevant specialists.
At what age should the first orthodontic check-up take place?
The American Association of Orthodontists (AAO) recommends that children have their first orthodontic check-up at around age 7. At this age the first permanent molars and incisors begin to come in, and the specialist can make an early assessment of the relationship between the jaws and teeth.
This does not mean the child will necessarily start treatment. For most children the examination results in a recommendation for monitoring only; for others it helps determine the right time for early intervention. For more information, see our at what age can you get clear aligners page. Our Invisalign for teens page may also be helpful for young people.
What should you pay attention to while using an appliance?
The three most important rules while using an appliance are to wear it for the time recommended by the dentist, to clean it regularly and not to miss check-up appointments. The information below is general; specific instructions are given by the dentist according to the type of device.
- First days: You may feel pressure on the teeth and palate, increased saliva and a foreign-body sensation. These complaints usually ease within a few days to two weeks.
- Speech: In the first days there may be a slight change in sounds such as "s" and "sh". Reading aloud speeds up adjustment; most children get used to it quickly.
- Eating: With fixed appliances, sticky foods (chewing gum, caramel), very hard foods, ice and habits such as biting nails or pens can damage the device. Removable appliances are usually taken out during meals.
- Cleaning: The teeth and the fixed device should be brushed after every meal. A removable device is cleaned with a soft brush and lukewarm water; hot water and harsh cleaners can distort its shape.
- If it is lost or broken: Do not try to repair a removable device yourself; contact the clinic. If the device is not worn for a long time, it may no longer fit. A lost or broken device can be remade; booking an appointment as soon as possible is recommended.
- Sports and music: Children with fixed devices should use a protective mouthguard in contact sports, and those who play wind instruments should know that they may need a period of adjustment in the first days.
- Storage: Keep a removable device in its case during meals rather than wrapping it in a napkin; most losses happen this way.
Should you choose an appliance or clear aligners?
Appliances and clear aligners are not interchangeable options; an appliance mostly focuses on jaw structure and growth, while clear aligners focus on the position of the teeth. Which one, or which sequence, is suitable is determined at the examination according to the patient's age and problem.
For example, with marked narrowness of the upper jaw, a fixed expansion appliance may be used first, followed by clear aligners to align the teeth. For mainly dental problems such as crowding, clear aligner treatment may be considered directly. At our clinic, clear aligner treatment is provided only with Invisalign; whether an appliance is needed in orthodontic plans with Invisalign is also assessed at the examination. For details, see our Invisalign, what are clear aligners and clear aligners vs. braces pages.
How is an appliance consultation planned in Çankaya, Ankara?
An appliance consultation in Çankaya, Ankara begins with an initial meeting with the orthodontist, an intraoral examination and, if considered necessary, an assessment of X-rays and photographs. Funda Sarıkaya Oral and Dental Health Polyclinic is located in Park Oran Ofis in the Oran neighborhood (next to Panora Mall, opposite One Tower Mall). During the orthodontic examination with Funda Pekyılmaz Sarıkaya, specialist orthodontist (Uzm. Dt.), whether an appliance is needed and the right timing are evaluated together. To book an appointment, you can use our contact page, and for other questions, take a look at our frequently asked questions and clear aligners in Ankara pages.